Up to the present date, a great quantity of air chambers located on the sole of footwear are known in the art. Those air chamber are generally located on the back portion of the sole, that is, in the heal, and serve to absorb the shock of the foot against the ground at the moment the user is exercising, be him walking or running. However, the present invention was designed with the objective of utilizing the energy generated by the pressure of the body weight on the heal of the footwear, comprising inside a compression bellows, in order to be utilized through a device comprising valves and a retainer, at the moment of the final detachment of the footwear from the ground by the means of an expansion bellows.